Detented cover assembly for vehicle deck lid lock

ABSTRACT

A detented cover assembly for use with a vehicle deck lid lock includes an apertured escutcheon mounted on the deck lid over the key cylinder of the lock. A cover is pivotally mounted on the escutcheon for movement about an axis normal to the deck lid between a closed position shielding the key cylinder from the environment and an open position where a key may be inserted through the escutcheon and into the key cylinder for unlocking rotation. A leaf spring mounted on the escutcheon is operable to detent the cover open against the closing bias of a torsion spring. The leaf spring includes a detenting portion that is normally located in the path of the cover movement toward closed position to provide a hold-open function. The leaf spring also includes an engagement portion that is engaged and pushed outwardly from the deck lid by a cam on the lock cylinder during its unlocking rotation. The engagement and detenting portions of the leaf spring are integrally connected to each other at a juncture which engages a portion of the escutcheon so as to be restrained from outward movement away from the deck lid. The outward camming of the engagement portion thus causes the detenting portion to be moved inwardly toward the deck lid in a first class lever action out of engagement with the cover so that closing movement of the cover under the bias of the torsion spring is achieved. The leaf spring nature of this lock cover assembly provides reliable operation despite manufacturing variations that may occur between the position of the lock with respect to the deck lid and escutcheon. The cover assembly is constructed so it may be removed from the deck lid with the lock remaining in position and still operable.

United States Patent 1191 Borlinghaus DETENTED COVER ASSEMBLY FOR VEHICLE DECK LID LOCK Hans J. Borlinghaus, Clarkston, Mich.

[75] Inventor:

[73] Assignee: General Motors Corporation,

Detroit. Mich.

[22] Filed: Aug. 2], 1974 [Zl] Appl. No.: 499,271

Primary E.\'zm11'ner-Paul R. Gilliam Assistant E.mrr1i:zer-Carl F. Pietruszka Allorney. Agent. or Firn1J. A. Kushman [57] ABSTRACT A detented cover assembly for use with a vehicle deck lid lock includes an apertured escutcheon mounted on the deck lid over the key cylinder of the lock. A cover Aug. 12, 1975 is pivotally mounted on the escutcheon for movement about an axis normal to the deck lid between a closed position shielding the key cylinder from the environment and an open position where a key may be inserted through the escutcheon and into the key cylinder for unlocking rotation. A leaf spring mounted on the escutcheon is operable to detent the cover open against the closing bias of a torsion spring. The leaf spring includes a detenting portion that is normally located in the path of the cover movement toward closed position to provide a hold-open function. The leaf spring also includes an engagement portion that is engaged and pushed outwardly from the deck lid by a cam on the lock cylinder during its unlocking rotation. The engagement and detenting portions of the leaf spring are integrally connected to each other at a juncture which engages a portion of the escutcheon so as to be restrained from outward movement away from the deck lid. The outward camming of the engagement portion thus causes the detenting portion to be moved inwardly toward the deck lid in a first class lever action out of engagement with the cover so that closing movement of the cover under the bias of the torsion spring is achieved. The leaf spring nature of this lock cover assembly provides reliable operation despite manufacturing variations that may occur between the position of the lock with respect to the deck lid and escutcheon. The cover assembly is constructed so it may be removed from the deck lid with the lock remaining in position and still operable.

3 Claims, 9 Drawing Figures DETENTED COVER ASSEMBLY FOR VEHICLE DECK LID LOCK BACKGROUND OF THE INVENTION This invention relates generally to detented cover assemblies for vehicle body deck lid locks.

Vehicle body deck lids conventionally include key operated locks that are utilized to unlock and unbolt latch assemblies which normally maintain the deck lids in closed positions. It has been known in the past to provide such locks with detented cover assemblies for shielding the locks from inclement weather conditions. These cover assemblies generally include an escutcheon fixedly mounted to the lock and pivotally supporting a cover movable about an axis generally normal to the plane of the adjacent deck lid between open and closed positions. A projection on the escutcheon normally maintains the cover in the open position, and a cam on the lock cylinder engages the cover to push it outwardly from the deck lid upon key rotation. This outward movement allows the cover to pass over the projection on the escutcheon and to return to closed position under a spring bias. This type of cover assembly generally has the lock and the escutcheon interconnected as a single unit so that the lock is simultaneously removed from the deck lid with the escutcheon.

SUMMARY OF THE INVENTION The present invention provides an improved detented cover assembly for a vehicle body deck lid lock in which a leaf spring mounted on the escutcheon which supports the cover provides the detenting action for holding the cover in the open position.

One feature of the invention is that the leaf spring of the lock cover assembly includes integral engagement and detenting portions. with the detenting portion of the spring normally being located in the path of cover movement so as to engage and hold the cover in the open position. and with the engagement portion being engaged by a cam on the rotable key cylinder of the lock during unlocking rotation so as to move this leaf spring portion outwardly and the detenting portion inwardly in a manner that allows a spring bias to return the cover to closed position. Another feature of the invention is that the detenting and engagement portions of the leaf spring define a generally V-shaped configuration with an obtuse angle therebetween and thejuncture of these portions engages the escutcheon to prevent outward movement of thisjuncture upon the outward movement of the engagement portion via the engagement with the key cylinder cam, and the detenting portion is thereby moved inwardly in a first class lever action to release the cover for closing movement. Another feature of the invention is that the leaf spring is mounted on the escutcheon by a support portion integrally connected to the engagement portion at a location spaced from the juncture of the engagement portion and the detenting portion in a manner that permits manufacturing variances between the position of the lock cylinder and the escutcheon without inhibiting the detenting and undetenting action of the cover. Another feature of the invention is that the cover assembly is mounted on the deck lid so it can be removed independently of the lock so that the lock is still operable upon removal of the cover assembly from the deck lid.

BRIEF DESCRIPTION OF THE DRAWINGS The above-specified features and other features, objects and advantages of the present invention are readily apparent from the following detailed description of the preferred embodiment and the drawings in which:

FIG. 1 is a partial view of a vehicle deck lid that supports a lock including a key cylinder and an associated cover asembly, according to this invention, with the cover of the cover assembly shown partially broken away and in a closed position;

FIG. 2 is a view similar to FIG. 1 but shows the cover detented in an open position by a leaf spring so the associated key cylinder may receive a key to permit unlocking rotation thereof:

FIG. 3 is a view similar to FIG. 2 but shows the cover just after key unlocking rotation of the key cylinder has caused the leaf spring to undetent the cover so that a spring bias may return the cover to the closed position of FIG. 1;

FIG. 4 is a sectional view of the deck lid and the cover assembly taken generally along line 44 of FIG. I, and shows an escutcheon and the cover of the cover assembly;

FIG. 5 is an enlarged sectional view of the cover assembly and the deck lid taken along line 5-5 of FIG. 1 and shows the manner in which the escutcheon that supports the cover is mounted on the deck lid as well as the manner in which the leaf spring is supported on the escutcheon;

FIG. 6 is an enlarged sectional view taken generally along line 6-6 of FIG. 2 and shows how the leaf spring engages the cover to maintain it in the open position of FIG. 2;

FIG. 7 is a sectional view taken in a similar direction to FIG. 6 but shows the manner in which a cam carried by the key cylinder engages the leaf spring to move it out of the path of the cover so that the cover may move to closed position;

FIG. 8 is an enlarged sectional view taken generally along line 8-8 of FIG. 1 and shows the manner in which the escutcheon pivotally supports the cover as well as showing a torsion spring that biases the cover to closed position; and

FIG. 9 is a view taken along line 9--9 of FIG. 8 and shows the escutcheon, the cover, and the torsion spring that provides the bias of the cover toward closed position.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring generally to FIG. 1, a vehicle body deck lid indicated by 10 of a generally planar configuration is shown as supporting a lock cover assembly according to this invention and indicated generally by I2. Additional reference to FIG. 4 shows that the deck lid 10 defines a recess 14 that receives the head 16 of a lock I8. This lock includes a conventional operator 20 that is adaptable to unlock and unlatch a conventional, but unshown, latch mechanism upon rotation of a suitable key 22 received by the lock 18. The unlatching action releases the deck lid 10 for movement from a closed position to an open position in a conventional manner so as to allow access to a vehicle body compartment, Reference back to FIG. I shows that the lock 18 includes a key cylinder 24 which is rotatable within the lock and defines a key opening 26 that opens outwardly with respect to deck lid 10 in a conventional manner. This key cylinder also includes an outwardly projecting cam 28 with inclined ends 30, see also FIG. 7. The cam 28 has an arcuate configuration when viewed as in FIG. 1 and is generated about the axis of rotation of key cylinder 24. The function of this cam 28 will be hereinafter described.

As best seen in FIGS. l3, The cover assembly 12 basically includes a generally rectangular escutcheon 32 mounted on the deck lid 10, a generally rectangular cover 34 pivotally mounted on the escutcheon 32 about the upper right-hand corner thereof, and a leaf spring 36 that is operable to detent the cover 34 in its FIG. 2 open position. Insertion of the key 22 into the key cylinder 24 and rotation thereof as shown in FIG. 3 causes the cam 28 on the key cylinder 24 to engage the leaf spring 36, in a manner that will be more fully hereinafter described, to undetent the cover 34 and allow a spring bias thereof to return the cover to its FIG. 1 closed position. In this closed position, the cover 34 shields the lock 18 from the environment and thus protects it from inclement weather conditions.

The escutcheon 32 may be manufactured as a Zinc die-casting and includes a central generally planar portion 38, FIGS. 2 and 3, that defines an aperture 40 exposing the lock 18 when cover 34 is open. A portion 41 of this central escutcheon portion 38 has a pointed configuration adjacent the aperture 40. At the periphery of its central portion 38, the escutcheon 32 defines an edge 42 that engages the deck lid 10 as seen in FIGS. 4 and 5. FIG. also shows a screw receptacle 44 of the escutcheon which receives a screw 46 that is threaded into a nut 48 secured to the inner side of deck lid by welds 50. A number of these screw and nut arrangements secure the escutcheon 32 to the deck lid 10 over the lock 18 generally in the manner illustrated by FIG. 4.

The cover 34 of cover assembly 12 may also be manufactured as a zinc die-casting and includes a central portion 52 that may receive a suitable decorative medallion. About this central portion 52, the cover 34 includes a peripheral edge 54 which engages the outwardly facing surface of the central portion 38 of the escutcheon at the periphery thereof in the closed position of FIG. I. Portions of this peripheral cover edge 54 slide along the central portion 38 of the escutcheon during cover movement between the open and closed positions. The cover 34 is pivotally supported on the escutcheon 32 for this movement by a pivotal support arrangement generally indicated by 56, but not shown in detail, in FIGS. 1 through 3. This support arrangement is located at the upper right-hand corner of escutcheon 32, as viewed in these Figures, and supports the cover 34 for movement parallel to the plane of deck lid 10 about an axis generally perpendicular to this plane.

The pivotal support arrangement 56 for cover 34 is illustrated in detail by FIG. 8 and includes an annular flange 58 of escutcheon 32, with this flange defining a round pintle aperture 60 that receives a pintle portion 62 extending inwardly from cover 34 toward the deck lid 10 with an annular cross section. A torsion spring 63 encircles escutcheon flange 58 and has one end 64 received within apertures 66 in the cover pintle portion 62. This spring end 64 also engages the inner end of escutcheon flange 58 to prevent the cover 34 from moving outwardly away from deck lid I0 and thus maintains the cover in position relative to the escutcheon. The other end 68 of spring 63 is illustrated in FIG. 9 and has a hook-shaped configuration that catches a lug 70 on the back side of escutcheon 32. The ends 64 and 68 of torsion spring 63 are thus respectively fixed to the cover 34 and the escutcheon 32 so that opening movement of cover 34 winds the torsion spring and thereby provides a bias tending to return the cover to its closed position.

As can be seen in FIGS. 1-3, the leaf spring 36 for detenting cover 34 in its open position basically includes a support portion 72, an engagement portion 74, and a detenting portion 76. The support portion 72 of the leaf spring has an elongated slightly curved configuration that extends in a generally vertical direction with its upper end suitably mounted to the back side of the central portion 38 of escutcheon 32. FIG. 5 shows the manner in which this mounting is accomplished by providing the upper end of support portion 72 with apertures 78 that receive lugs 80 of the central escutcheon portion 38, these lugs being formed over the spring portion to secure it in position. As also seen in FIG. 5, from below the lower lug 80, spring support portion 72 extends inwardly toward the deck lid 10. The lower end of spring support portion 72 is integrally connected to the lower end of the spring engagement portion 74 which also has a slightly curved configuration and extends alongside the support portion 72 to define a somewhat hook-shaped configuration with a double shank. The engagement portion 74 has a tip 82 that is located within the arcuate path of movement of key cylinder cam 28 as can be seen by FIG. 2. This tip 82 is aligned with aperture 40 and is located inwardly toward the deck lid from the escutcheon central portion 38, as can be seen in FIG. 6, and the engagement portion 74 extends outwardly from its tip 82 toward the escutcheon central portion 38. The detenting portion 76 of spring 36 extends in a generally vertical direction as seen in FIGS. 1-3 and has its lower end integrally connected to the upper end of engagement portion 74 at a juncture 83 which engages the backside of escutcheon central portion 38 at its pointed portion 41, see FIGS. 1-3 in addition to FIG. 6. The upper end of detenting portion 76 is formed in a generally hook-shaped configuration to define a detenting surface 84 and a ramp surface 86, FIG. 6. The upper end of this detenting portion 76 normally extends outwardly through the aperture 40 in escutcheon central portion 38, as seen in FIG. 6, and the detenting and engagement portions 74 and 76 form a generally V-shaped configuration with an obtuse included angle.

The cover 34 normally assumes its FIG. I closed position except when a person desires to unlock lock 18. At such times, the person manually moves the cover 34 to the FIG. 2 position about the pivotal support axis provided by support arrangement 56 and against the bias of the torsion spring 63 of this support arrangement. Both the left and right'hand portions of cover edge 54 will engage the ramp surface 86 of the leaf spring detenting portion 76 so as to momentarily depress the detenting portion inwardly toward lock 18 as this opening cover movement proceeds. When the cover reaches its open position, the detenting portion 76 of leaf spring 36 moves outwardly through the aperture 40 in escutcheon central portion 38 and thereby positions the detenting surface 84 thereof in the path of movement of cover edge 54. The torsion spring bias of pivotal support arrangement 56 then biases the cover 34 counterclockwise to engage the cover edge 54 with detenting surface 84, FIGS. 2 and 6. This engagement maintains cover 34 in an open position so that the lock 18 is freely accessible for a person desiring to insert key 22 into the key cylinder 24 for unlocking rotation.

The unlocking rotation of'key cylinder 24 moves the cam 28 toward and into engagement with the tip 82 on engagement portion 74 of leaf spring 36, see FIG. 3. This engagement causes the engagement portion 74 to move outwardly away from the lock 18 and the deck lid 10, see also FIG. 7. The juncture 83 of the engagement portion 74 and the detenting portion 76 of the leaf spring, however, is engaged with the pointed portion 41 of central escutcheon portion 38 and cannot move outwardly with the tip 82 of engagement portion 74. Since the detenting portion 76 defines an obtuse generally V- shaped configuration with respect to the engagement portion 74, as shown in FIGS. 6 and 7, the outward movement of tip 82 causes the detenting portion 76 to move inwardly toward the lock 18 in a first class lever action pivoting about the juncture 83 between spring portions 74 and 76. This causes inward movement of the upper end of detenting portion 76 back through the aperture 40 in escutcheon 38 when the key cylinder 24 has been rotated enough to unlock l8 and the cover 34 is then free to automatically move back to its closed position under the bias provided by the torsion spring 63 of pivotal support arrangement 56.

The leaf spring 36 is capable of functioning despite manufacturing variances that may be present in the inward or outward positioning of lock 18, generally to the right or to the left as viewed in FIG. 4, with respect to the escutcheon and the leaf spring. This is due to the resilient nature of the leaf spring and the flexing it can stand in operation.

Also, the manner in which the cover assembly 12 is mounted on the deck lid 10, and not directly to the lock 18, allows the cover assembly to be removed without removal of the lock. Thus, lock 18 is capable of operating even if the cover assembly 12 is removed and will thus still provide its locking and unlocking function for the latch mechanism of deck lid 10.

The invention thus provides an improved detented cover assembly for a vehicle body deck lid lock.

What is claimed is:

1. In a vehicle body deck lid supporting a lock including a rotatable key cylinder with an outwardly facing key opening for receiving an appropriate key to permit unlocking rotation of the cylinder, a detented cover assembly for the lock comprising:

an escutcheon mounted on the deck lid over the lock and defining an aperture allowing the key to be inserted into the key cylinder;

a cover pivotally mounted on the escutcheon for movement between a closed position covering the aperture in the escutcheon so as to shield the lock from the environment and an open position where the key may be inserted through the escutcheon and into the key cylinder;

spring means biasing the cover to the closed position;

a cam carried by the key cylinder for rotation therewith; and

a leaf spring mounted on the escutcheon and including engagement and detenting portions integral with each other, the detenting portion of the leaf spring being normally located in the path of cover movement toward closed position so as to engage and hold the cover in open position against the bias of the spring means, the engagement portion of the leaf spring being engaged by the cam on the key cylinder during unlocking rotation thereof so as to move this portion of the spring outwardly away from the deck lid, and the juncture of the engagement and detenting portions engaging the escutcheon so as to be restrained from outward movement with the engagement portion in a manner that causes the detenting portion to concomitantly move inward toward the deck lid so as to disengage the open cover and allow closing movement thereof under the bias of the spring means.

2. In a vehicle body deck lid supporting a lock including a rotatable key cylinder with an outwardly facing key opening for receiving an appropriate key to permit unlocking rotation of the cylinder, a detented cover assembly for the lock comprising:

an escutcheon mounted on the deck lid over the lock and including a central portion defining an aperture allowing the key to be inserted into the key cylinder.

a cover pivotally mounted on the escutcheon for movement between a closed position covering the aperture in the central portion of the escutcheon so as to shield the lock from the environment and an open position where the key may be inserted through the escutcheon and into the key cylinder;

a torsion spring biasing the cover to the closed position;

a cam carried by the key cylinder for rotation therewith; and

a leaf spring mounted on the escutcheon between the central portion thereof and the deck lid and including engagement and detenting portions integral with each other and defining an obtuse generally V-shaped configuration, the detenting portion of the leaf spring normally extending through the aperture in the central portion of the escutcheon so as to be located in the path of cover movement toward closed position and to thereby engage and hold the cover in open position against the bias of the torsion spring, the engagement portion of the leaf spring being engaged by the cam on the key cylinder during unlocking rotation thereof so as to move this portion of the spring outwardly away from the deck lid, and the juncture of the engagement and detenting portions engaging the central portion of the escutcheon so as to be restrained from outward movement with the engagement portion in a manner that causes the detenting portion to concomitantly move inwardly through the escutcheon aperture toward the deck lid and to thereby disengage the open cover and allow closing movement thereof under the bias of the spring means.

3. In a vehicle body deck lid supporting a lock including a rotatable key cylinder with an outwardly facing key opening for receiving an appropriate key to permit unlocking rotation of the cylinder, a detented cover assembly for the lock comprising:

an escutcheon mounted on the deck lid over the lock and including a central portion defining an aperture allowing the key to be inserted into the key cylinder;

cover pivotally mounted on the escutcheon for movement between open and closed positions about an axis generally normal to the deck lid, the cover being located over the aperture in the escutcheon so as to shield the lock from the environment while in the closed position and exposing this aperture while in the open position so that a key may be inserted through the escutcheon and into the key cylinder;

torsion spring biasing the cover to the closed position;

cam carried by the key cylinder for rotation therewith; and

an integral leaf spring located between the central portion of the escutcheon and the deck lid and including support, engagement and detenting portions, the support portion of the leaf spring having an elongated configuration with one end thereof mounted to the central portion of the escutcheon and with the other end thereof extending inwardly toward the deck lid, the engagement portion of the leaf spring being joined to the inwardly extending end of the support portion and being engaged by the cam on the key cylinder during unlocking rotation thereof so as to move this portion of the spring outwardly away from the deck lid, the detenting portion of the leaf spring being integrally connected to the engagement portion so as to define an obtuse generally V-shaped configuration with the juncture of these portions engaging the central portion of the escutcheon, the detenting portion having a detenting surface normally extending outwardly through the escutcheon aperture so as to be located in the path of cover movement toward closed position so that this surface engages and holds the cover in the open position against the bias of the torsion spring, and the engagement of the escutcheon with the juncture between the engagement and detenting portions preventing outward movement of this juncture with the engagement portion under the impetus of the key cylinder cam rotation so that the detenting portion of the leal spring moves inwardly in a first class level action to move the detenting surface inwardly through the central escutcheon aperture and out of engagement with the open cover and to thereby allow the torsion spring to move the cover to closed position.

=l l =I 

1. In a vehicle body deck lid supporting a lock including a rotatable key cylinder with an outwardly facing key opening for receiving an appropriate key to permit unlocking rotation of the cylinder, a detented cover assembly for the lock comprising: an escutcheon mounted on the deck lid over the lock and defining an aperture allowing the key to be inserted into the key cylinder; a cover pivotally mounted on the escutcheon for movement between a closed position covering the aperture in the escutcheon so as to shield the lock from the environment and an open position where the key may be inserted through the escutcheon and into the key cylinder; spring means biasing the cover to the closed position; a cam carried by the key cylinder for rotation therewith; and a leaf spring mounted on the escutcheon and including engagement and detenting portions integral with each other, the detenting portion of the leaf spring being normally located in the path of cover movement toward closed position so as to engage and hold the cover in open position against the bias of the spring means, the engagement portion of the leaf spring being engaged by the cam on the key cylinder during unlocking rotation thereof so as to move this portion of the spring outwardly away from the deck lid, and the juncture of the engagement and detenting portions engaging the escutcheon so as to be restrained from outward movement with the engagement portion in a manner that causes the detenting portion to concomitantly move inward toward the deck lid so as to disengage the open cover and allow closing movement thereof under the bias of the spring means.
 2. In a vehicle body deck lid supporting a lock including a rotatable key cylinder with an outwardly facing key opening for receiving an appropriate key to permit unlocking rotation of the cylinder, a detented cover assembly for the lock comprising: an escutcheon mounted on The deck lid over the lock and including a central portion defining an aperture allowing the key to be inserted into the key cylinder. a cover pivotally mounted on the escutcheon for movement between a closed position covering the aperture in the central portion of the escutcheon so as to shield the lock from the environment and an open position where the key may be inserted through the escutcheon and into the key cylinder; a torsion spring biasing the cover to the closed position; a cam carried by the key cylinder for rotation therewith; and a leaf spring mounted on the escutcheon between the central portion thereof and the deck lid and including engagement and detenting portions integral with each other and defining an obtuse generally V-shaped configuration, the detenting portion of the leaf spring normally extending through the aperture in the central portion of the escutcheon so as to be located in the path of cover movement toward closed position and to thereby engage and hold the cover in open position against the bias of the torsion spring, the engagement portion of the leaf spring being engaged by the cam on the key cylinder during unlocking rotation thereof so as to move this portion of the spring outwardly away from the deck lid, and the juncture of the engagement and detenting portions engaging the central portion of the escutcheon so as to be restrained from outward movement with the engagement portion in a manner that causes the detenting portion to concomitantly move inwardly through the escutcheon aperture toward the deck lid and to thereby disengage the open cover and allow closing movement thereof under the bias of the spring means.
 3. In a vehicle body deck lid supporting a lock including a rotatable key cylinder with an outwardly facing key opening for receiving an appropriate key to permit unlocking rotation of the cylinder, a detented cover assembly for the lock comprising: an escutcheon mounted on the deck lid over the lock and including a central portion defining an aperture allowing the key to be inserted into the key cylinder; a cover pivotally mounted on the escutcheon for movement between open and closed positions about an axis generally normal to the deck lid, the cover being located over the aperture in the escutcheon so as to shield the lock from the environment while in the closed position and exposing this aperture while in the open position so that a key may be inserted through the escutcheon and into the key cylinder; a torsion spring biasing the cover to the closed position; a cam carried by the key cylinder for rotation therewith; and an integral leaf spring located between the central portion of the escutcheon and the deck lid and including support, engagement and detenting portions, the support portion of the leaf spring having an elongated configuration with one end thereof mounted to the central portion of the escutcheon and with the other end thereof extending inwardly toward the deck lid, the engagement portion of the leaf spring being joined to the inwardly extending end of the support portion and being engaged by the cam on the key cylinder during unlocking rotation thereof so as to move this portion of the spring outwardly away from the deck lid, the detenting portion of the leaf spring being integrally connected to the engagement portion so as to define an obtuse generally V-shaped configuration with the juncture of these portions engaging the central portion of the escutcheon, the detenting portion having a detenting surface normally extending outwardly through the escutcheon aperture so as to be located in the path of cover movement toward closed position so that this surface engages and holds the cover in the open position against the bias of the torsion spring, and the engagement of the escutcheon with the juncture between the engagement and detenting portions preventing outward movement of this juncture with the engagement portion under the impetus of the key cylinder cam rotatioN so that the detenting portion of the leaf spring moves inwardly in a first class level action to move the detenting surface inwardly through the central escutcheon aperture and out of engagement with the open cover and to thereby allow the torsion spring to move the cover to closed position. 